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Discussion Starter #1 (Edited)
EDIT: There were 2 issues: 1) the XLS voltage of .775 doesn't play nice with some AVR's. I purchased a CleanBox and that fixed it immediately. 2) I had the Mag tuned to about 60 and once I tuned it to 43ish Hz it sounds GREAT!!!

CC: @Erich H

So I built a 1.2 cuft box for some DIYSG magnum 12's tuned to approx 45hz with a 300W 8Ohm Crown XLS2002 amp. It seems that I have to run it at max gain just to keep up with my mains during calibration which are Paradigm Prestige F75's (5" cones). The cone barely moves too.

When I'm at max gain I have some feedback or noise. Thoughts on why I need to run this at Max gain? I currently have 2 zip ties in the speaker holes so I can remove the speaker until I'm done veneering and screwing around. Would that "broken airtight seal" kill the volume that much.

I'm running the amp in .775V mode which is what I think I'm supposed to do. How can I get rid of that noise? I put a 3 prong to 2 prong adapter to limit the ground. I get that it's a high sensitivity 99.5dB driver so I'm not 100% surprised of the noise at max gain, but I feel at max gain it should be way out of proportion with my fronts not just keeping up.

Also, for my tests I was running at -25dB. I wanted to see if I could have the sub (MBM) run way way hotter than my fronts. I have the AVR at +6dB for the sub (MBM) and it's just keeping pace.
 

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Discussion Starter #2
Modeled in this box this driver should be able to hit 105dB at 33Hz and hit reference 115dB at 55Hz.
 

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Discussion Starter #3
correction the XLS2002 can do up to 375W at 8 Ohm!
 

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What did you do to set it up/integrate it?

You need to get in alignment with your other speaker. Time/distance and polarity wise. Not sure if the amp your using is like some that reverses polarity like the Inuke and my Sunfire amp flips it 180 when using XLR vs the RCAs.

Edit looking at a pic online of the back of the amp and the XLR pinout it looks like it will reverse the polarity just the Inuke and my Sunfire since they wire it the same using the 3 pin as negative. That is the current standard for XLR.
 

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Discussion Starter #5
What did you do to set it up/integrate it?

You need to get in alignment with your other speaker. Time/distance and polarity wise. Not sure if the amp your using is like some that reverses polarity like the Inuke and my Sunfire amp flips it 180 when using XLR vs the RCAs.

Edit looking at a pic online of the back of the amp and the XLR pinout it looks like it will reverse the polarity just the Inuke and my Sunfire since they wire it the same using the 3 pin as negative. That is the current standard for XLR.
At this point I’m not looking to integrate it. I just want to run it hot and loud to test them.
Running at Max gain shouldn’t they be abnormally loud and not blend well? When I turn up the gain on my other subs to almost max it’s in appropriately and noticeably hot. I have them turned off as well as room correction for my experiment
I did switch the wires and it got a bit louder. I wonder if I use better speaker wire. I’ve got 16 gauge on there now. It was just some spare test wire I had
 

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Discussion Starter #6
What did you do to set it up/integrate it?

You need to get in alignment with your other speaker. Time/distance and polarity wise. Not sure if the amp your using is like some that reverses polarity like the Inuke and my Sunfire amp flips it 180 when using XLR vs the RCAs.

Edit looking at a pic online of the back of the amp and the XLR pinout it looks like it will reverse the polarity just the Inuke and my Sunfire since they wire it the same using the 3 pin as negative. That is the current standard for XLR.
I should note I’m using RCA
 

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You need to set them up like you would any speaker or sub you add to a system(distance,x-overs, eq etc).

Have you tested just the 12" alone and took some close mic sweeps with REW to see what it is actually doing as far as FR and SPL? That is what I would do so I could see what the speaker is actually doing and see some numbers and then go from there if you think it is lacking output.

And yes it will affect output if you have air leaks around the speaker where the zip ties are holding it up from making an airtight seal.
 

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I should note I’m using RCA
If you are using RCA to XLR it still flips polarity since the amps XLR pinout is opposite of RCA. You can check for yourself using REW and looking at the impulse.

Edit I see your amp has RCA inputs also. So nevermind my comment about the XLR. I would still check if the RCA on it gives you the same polarity as all of your other speakers. You will need to know this eventually anyway as you usually want all your speakers to have the same polarity.
 

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Sounds like you need to buy a Cleanbox Pro:
https://www.parts-express.com/art-cleanboxpro-stereo-balanced-unbalanced-converter--245-868
I have 3 of these, they work great. Flat to at least 8hz, suitable for mid-bass and subs. I wouldn't use them on tweeters for HiFi music though...

That will fix your level and noise problem. As that gives you real XLR, not fake XLR.
It is designed to convert between the two voltages, correctly.

Beyond that, it's just placement, room modes, and lack of EQ/Delay/Phase. A UMIK and REW should detect it.


Ported and Horned subs minimize excursion, and pro subs don't move far to start with. It should follow the box-model once you get real XLR to it. The leak will reduce some SPL and add some THD, but shouldn't be too horrible. Nothing like what you are describing.

That said: 12's aren't that loud...

Most basshead's need 4 PA-460's to have sufficient SPL in the mid-bass, so I'm not surprised if turns out that a single 12 still isn't "loud enough" for an AVS DIY'er hehe! :p
 

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If you are using RCA to XLR it still flips polarity since the amps XLR pinout is opposite of RCA. You can check for yourself using REW and looking at the impulse.

Edit I see your amp has RCA inputs also. So nevermind my comment about the XLR. I would still check if the RCA on it gives you the same polarity as all of other speakers. You will need to know this eventually anyway as you usually want all your speakers to have the same polarity.
So if I’m understanding you the + & ground of the RCA is connecting to pins that doesn’t correlate w/ the RCA polarity?

I am using an XLR to RCA adapter so I feel this is prudent information.
 

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Most basshead's need 4 PA-460's to have sufficient SPL in the mid-bass, so I'm not surprised if turns out that a single 12 still isn't "loud enough" for an AVS DIY'er hehe! :p
I am cautious to ask you this but what is sufficient SPL and what frequency range? (55-150hz?)
 

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Discussion Starter #13
Sounds like you need to buy a Cleanbox Pro:
https://www.parts-express.com/art-cleanboxpro-stereo-balanced-unbalanced-converter--245-868
I have 3 of these, they work great. Flat to at least 8hz, suitable for mid-bass and subs. I wouldn't use them on tweeters for HiFi music though...

That will fix your level and noise problem. As that gives you real XLR, not fake XLR.
It is designed to convert between the two voltages, correctly.

Beyond that, it's just placement, room modes, and lack of EQ/Delay/Phase. A UMIK and REW should detect it.


Ported and Horned subs minimize excursion, and pro subs don't move far to start with. It should follow the box-model once you get real XLR to it. The leak will reduce some SPL and add some THD, but shouldn't be too horrible. Nothing like what you are describing.

That said: 12's aren't that loud...

Most basshead's need 4 PA-460's to have sufficient SPL in the mid-bass, so I'm not surprised if turns out that a single 12 still isn't "loud enough" for an AVS DIY'er hehe! /forum/images/smilies/tongue.gif
I’ll definitely pick up that bass box pro

I have some Rythmik 12’s that currently run circles around this. I hope the airflow is the issue.

Dirac doesn’t allow gain changes after calibration so I intended to run these hot on the amp side. Currently they can’t be run hot. The gain match is max gain
 

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So if I’m understanding you the + & ground of the RCA is connecting to pins that doesn’t correlate w/ the RCA polarity?

I am using an XLR to RCA adapter so I feel this is prudent information.
Yep from the amps I have when using anything XLR to XLR or XLR to RCA the polarity is reversed compared to the AVR built-in amp or my Sunfire amp using RCA to RCA.

I know other people found the same thing and posted about it in the Inuke amp testing thread. As far as I can see it looks to me like most amps that use XLR use the latest PIN standard EIA Standard RS-297-A so most people are going to have this issue and they should verify the polarity of the amps they are using as different amps and different connection can cause issues.

Link to thread where it is discussed throughout the thread in different places. https://www.avsforum.com/forum/155-diy-speakers-subs/2911854-nu6000dsp-amp-rundown.html#post54638692
 

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Discussion Starter #15
Most basshead's need 4 PA-460's to have sufficient SPL in the mid-bass, so I'm not surprised if turns out that a single 12 still isn't "loud enough" for an AVS DIY'er hehe! /forum/images/smilies/tongue.gif
I am cautious to ask you this but what is sufficient SPL and what frequency range? (55-150hz?)
Not sure. I figured max gain would be out of proportion with my fronts. That was the initial test.
 

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Discussion Starter #16
You need to set them up like you would any speaker or sub you add to a system(distance,x-overs, eq etc).

Have you tested just the 12" alone and took some close mic sweeps with REW to see what it is actually doing as far as FR and SPL? That is what I would do so I could see what the speaker is actually doing and see some numbers and then go from there if you think it is lacking output.

And yes it will affect output if you have air leaks around the speaker where the zip ties are holding it up from making an airtight seal.
I have a mic and have to get an old nvidia driver that works with REW. Nvidia drivers about 6 months ago broke ASIO4All.
 

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I currently have 2 zip ties in the speaker holes so I can remove the speaker until I'm done veneering and screwing around. Would that "broken airtight seal" kill the volume that much.
Depending upon how much air is allowed to leak it will absolutely reduce SPL. With a big enough leak, you've kind of turned it into a dipole speaker and at low frequencies it will cancel itself out. If you've got it kinda snugged down a little other than the zip ties then that's probably not it (I'd expect *something* decent out of it) and it's something else that's been mentioned.
 

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Discussion Starter #18
I currently have 2 zip ties in the speaker holes so I can remove the speaker until I'm done veneering and screwing around. Would that "broken airtight seal" kill the volume that much.
Depending upon how much air is allowed to leak it will absolutely reduce SPL. With a big enough leak, you've kind of turned it into a dipole speaker and at low frequencies it will cancel itself out. If you've got it kinda snugged down a little other than the zip ties then that's probably not it (I'd expect *something* decent out of it) and it's something else that's been mentioned.
I’ll take them out.

How do others take out the driver? Just tip the box?
 

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The amp is 9 months old but I’ve never used it. What are the chances it’s the amp and how can I measure it? I have a multimeter.
 

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Sounds like you need to buy a Cleanbox Pro:
https://www.parts-express.com/art-cleanboxpro-stereo-balanced-unbalanced-converter--245-868
I have 3 of these, they work great. Flat to at least 8hz, suitable for mid-bass and subs. I wouldn't use them on tweeters for HiFi music though...

That will fix your level and noise problem. As that gives you real XLR, not fake XLR.
It is designed to convert between the two voltages, correctly.

Beyond that, it's just placement, room modes, and lack of EQ/Delay/Phase. A UMIK and REW should detect it.


Ported and Horned subs minimize excursion, and pro subs don't move far to start with. It should follow the box-model once you get real XLR to it. The leak will reduce some SPL and add some THD, but shouldn't be too horrible. Nothing like what you are describing.

That said: 12's aren't that loud...

Most basshead's need 4 PA-460's to have sufficient SPL in the mid-bass, so I'm not surprised if turns out that a single 12 still isn't "loud enough" for an AVS DIY'er hehe! /forum/images/smilies/tongue.gif
I’ll have the bassbox in 3 hours. Do I keep the input sensitivity at .775 or move it to 1.4 now that I’m on XLR
 
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